Acetoacetic ester-formaldehyde resins



Patented Mar. 24, 1942 UNITED STATE ACETOACETIC ESTER-FORMALDEHYDEBESINS Gaetano F. DAlelio, Plttsfleld, Mass assignor to General ElectricCompany, a corporation of New York -.No Drawing.

1 Claim.

The present invention relates to resinous compositionsand to theproduction of the same.

a. This application is a continuation-in-part-of my copendingapplications, Serial No. 169,465, filed October 16, 1937, now Patent No.2,239,440, issued April 22, 1941, and Serial No. 205,007, filed April29, 1938, both applications being assigned to the same assignee as thepresent invention.

This invention is based on the discovery that ethylene compounds inwhich both bonds of the beta carbon atoms of the ethylene molecule areattached to two carbon atoms which are at least double bonded, are veryactive polymerizing substances.

More particularly, the grouping of the class of substances fallingwithin the scope of the present invention may be represented, generally,as

(LR cm=o C-X i II where R is a radical selected from the class consisting of alkyl (e. g., -CH3, C2Hs) aralkyl (e. g.,--CHzCeH5) aryle,,g. CsH5) and alkaryl Application August 13', 1938, Serial No. 224,799

an example of an organic compound which may be represented by thegraphic formula COR \COOR' and methylene acetyl acetone is an example of(e. g., --CsH4CHa), and X'is a radical selected 7 ing within the classof substances mentioned are methylene ethyl acetoacetate,

' coon,

CHFC

cocoa, and methylene acetyl acetone,

CHFC

o 0 cm,

Methylene ethyl acetoacetate and methylene V acetyl acetone are examplesof organic compounds which may be represented by the graphic formulawhere and K have the meanings given above. More particularly methyleneethyl acetoacetate is n more particularly the formula an organiccompound which may be represented by the graphic formula c o a cH==o CORwhere R and R. are the same or different radicals of the above-mentionedclass.

7 While it is possible to prepare the methylene derivatives of thisinvention by other methods, I, prefer, as disclosed in my above notedcopending applications, to prepare the group of compounds describedherein through a reaction between an aldehyde, such as, formaldehyde andan organic compound containing a CH2 group adjacent to two carbon atomswhich are at least double bonded. One of these double-bonded carbonatoms is connected to a radical represented in the above formulas byBand the other to a radical designated in the above formulas as X(R.' orOR) In other words; formaldehyde is caused to react with anorganiccompound hav 1 ing the graphic formula "ll, 1 f CH:

con 0111 0'03: v v where R and K have the meanings above given withparticular reference to the formulas for the corresponding methylenederivatives. For ex-- ample, an aqueous solution of formaldehyde maybereacted, as hereafter more fully described, with organic compoundsformulas c o R 0g:

0 0 R and c 0 n 0 HI having the graphic ous complexes.

to form the corresponding methylene derivatives c o n C H2=C c o R and nc o a where R and R have the meanings above given.

As an example of the reaction I may use formaldehyde and ethylacetoacetate. A methylol derivative first forms, and this is dehydratedto the methylene compound, followed by polymerization. Low, molecularweight products in the form of a light yellow oil may be obtained duringthis process. On further heating water may be eliminated by anintermolecularreaction between the CH3 group of one molecule and the=C=O of another molecule to give higher resin- These side' reactionswould not occur if anon-reactive radical such as a benzoyl replaced theacetyl of acetoacetic ester to give methylene benzoyl acetic, ester byreaction with formaldehyde COOH ClIz

temperature up to the reflux temperature of the aldehyde. Pressure maybe used to obtain temperatures higher than the reflux temperature offormaldehyde.

The water in the reaction product may be re-,

moved'by dehydration underreduced or atmospheric pressures either athigh or low temperatures.

Example 1 10 parts (0.1 mol) of acetyl acetone 8.9 parts of 37.1%formalin solution (0.11 mol HCHO) i 0.1-part (0.0025 mol) of sodiumhydroxide in 10 parts of water were refluxed for 90 minutes.

The original acetyl acetone was yellow in color and the condensationproduct was of the same shade.

Mols

Acetyl acetone 1. Formaldehyde 1. Sodium hydroxide 0.025

Example 2 26 parts (0.2 mol) of ethyl acetoacetate 18 parts of 37.1%formalin solution (0.222 mol I HCHO) and 0.26 part of morpholine werecondensed with formaldehyde to give the I methylene derivative.

The condensation between formaldehyde and an organic compound of thekind with which this invention is concerned will proceed under acid oralkaline conditions, though alkaline conditions are preferred. Thealkali used in the condensa tion, suehas sodium hydroxide, sodiumcarbonate, morpholine or the like may be neutralized before theisolation of the resinous bodies.

It may be advisable in some instances to carry out the reactions in thepresence of polymerization inhibitors, e. g. hydroquinone, and thedehydration may be assisted by dehydration agents such as phosphoricacid, etc.

Although an amount of formaldehyde in excess, as well as in a quantityinsufficient to react with these compounds containing an active -CH2group in molecular equivalents may be used, it is preferable to use atleast an equivalent mol ratio; yet an excess actually is used inquantities so adjusted as to keep the formation of methylene bisderivatives, which are formed as by-products, at a The condensation offormaldehyde with organic compounds containing an active CH2 group maybe carried out at any temperature from room were refluxed for minutes.fThe solution was originally homogeneous and on reflux an insolublephase was formed. It was possible to remove water at 70 C., leaving aviscous resin insoluble in water but soluble in alcohol. On furtherheating at about C. a very insoluble resin resulted. In the aboveformula the mol ratios of ethyl acetoacetate and formaldehyde areapproximately as follows: Y

Mols' Ethyl acetoacetateu 1 Formaldehyde". 1.11

' Example 3 in 10 parts of water were added together and refiuxed fortwo hours. The water was then removed by distillation, which left abrownish red .resin that was thermoplastic and insoluble in water andalcohol. In the above formula the mol ratios of components areapproximately as follows:

Mols

Ethyl acetoacetate 1 Formaldehyde More than 2 mols, specificallyabout2.22 mols Sodium hydroxide 0.0375

Example 4 26 parts of acetoacetic ester, specifically ethyl acetoacetate18 parts of formalin solution 0.3 part of sodium hydroxide in 10 partsof water were mixed and immediate During the reaction the solution washomogeneous and on cooling a separation into Example 13.2 parts ofdimethyl malonate 8.9 parts of 37.1% formalin solution 0.1 part ofsodium hydroxide in 5 parts of water were mixed, and resulted in ahomogeneous solution with the evolution of heat. Water was removed bydistillation (or evaporation) and on further heating to about 150 C. athermoplastic resin similar to rosin was obtained.

Example 6 10 parts (0.1 mol) of acetyl acetone 26.7 parts of 37.1%formalin solution (0.33 mol HCHO) and 0.1 part (0.0025 mol) of sodiumhydroxide in 10 parts of water were refluxed for three hours, the waterwas removed by evaporation at 70 C., and the product was heated to 160C. Continued heating produced a plastic mass which is rubbery when hotand hard and brittle when cool. In the above formulas the mol ratios ofI were mixed in a flask and with stirring were allected distillate maybe polymerized in the presence or absence of light. with or withoutperoxides or polymerization catalysts to low and high molecular weightpolymers of glass-like clarity highly resistant to chemical action andto chemical solvents-such as ethyl alcohol, ethyl acetate, concentratedalkali solutions and concentrated acid solutions. The separation of verylow molecular weight products from high molecular weight products may beaccomplished by specific solvents for the low molecular weight productssuch as ethyl alcohol, etc.

The low molecular weight polymers may be converted to polymers of highermolecular weight either by heating or by destructive distillation tomonomers which are recondensed and repolymerized.

lowed to stand for 12-24 hours. The product was then dehydrated undervacuum until about 150 parts of distillate were obtained and thendiscarded. The distillation was then continued as far as possible,usually at a vacuum of 10-15 mmI Hydroquinone may be added duringdifferent stages of the condensation, and zinc chloride or phosphoricacid may be added to assist the dehydration of the methylol derivativebefore 0 during the dehydration process.

From the foregoing description, more particularly from Example 2, itwill be seen that the present invention provides a method of preparing aresinous composition which comprises refluxing under heat ethylacetoacetate and an aqueous solution of formaldehyde in the ratio of onemol of the former to substantially more than one mol of the latter inthe presence of morpholine as a catalyst, said morpholine being presentin the ratio of about 1 part of morpholine to 100 parts of ethylacetoacetate, heating the reaction mixture at about C. to remove thewater and then heating at about 160 C. until an insoluble resin results.7

What I claim as new and .desire to secure by Letters Patent of theUnited States is:

The method of-preparing a resinous composition which comprises refluxingunder heat ethyl acetoacetate and an aqueous solution of formaldehyde inthe ratio of one mol of the former to substantially more than one mol ofthe latter in the presence of morpholine as a catalyst, said morpholinebeing present in the ratio of about 1 part of morpholine to parts ofethyl acetoacetate, heating the reaction mixture at about 70 C. toremove the water and then heating at about C. until an insoluble resinresults.

GAETANO F. D'ALELIO.

